WO2019244872A1

WO2019244872A1 - Motor

Info

Publication number: WO2019244872A1
Application number: PCT/JP2019/024043
Authority: WO
Inventors: 康介山浦
Original assignee: 株式会社デンソー
Priority date: 2018-06-20
Filing date: 2019-06-18
Publication date: 2019-12-26
Also published as: CN112368915B; US20210057966A1; DE112019003115T5; JP7047619B2; CN112368915A; JP2019221074A; US11316411B2

Abstract

This motor comprises a yoke (14), an armature (15), a brush holder (16) and a ground member (33). The yoke has the shape of a bottomed cylinder that has an inner surface to which a magnet (13) is affixed. The armature is contained within the yoke. The brush holder is arranged in an opening of the yoke, and holds a feed brush (24) for supplying an electric current to the armature, and a bearing (26) that axially supports a rotary shaft (18) of the armature. The ground member is in contact with the bearing and the yoke. The ground member is affixed to a ground terminal (32) that is held by the brush holder.

Description

motor

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2018-117190 filed on June 20, 2018, the contents of which are incorporated herein by reference.

The present disclosure relates to a motor.

Conventionally, as a motor, a yoke to which a magnet is fixed, an armature housed in the yoke, a power supply brush arranged in an opening of the yoke to supply current to the armature, and a rotating shaft of the armature And a brush holder for holding a bearing for supporting the shaft. In such a motor, electric noise is generated due to, for example, the power supply brush slidingly contacting the commutator of the armature, and the electric noise is also transmitted to the rotating shaft. There is one that includes a grounding member to be contacted to prevent radiation of electric noise to the surroundings (for example, see Patent Document 1).

Japanese Patent No. 6051129

However, in the above-described motor, the connection of the ground member is determined by interposing the ground member between the yoke and the gear housing fastened to the yoke and fastening together. Therefore, when the grounding member is fastened at an incorrect position, the gear housing is fixed, so that there is a problem that the contact state of the grounding member cannot be confirmed.

An object of the present disclosure is to provide a motor that can favorably provide a grounding member that contacts a bearing and a yoke.
To achieve the above object, a motor according to an embodiment of the present disclosure includes a yoke (14), an armature (15), a brush holder (16), and a ground member (33). The yoke has a bottomed cylindrical shape with a magnet (13) fixed to the inner surface. The armature is housed in the yoke. The brush holder is disposed in an opening of the yoke, and includes a power supply brush (24) for supplying a current to the armature and a bearing (26) for supporting a rotating shaft (18) of the armature. Hold. The ground member is in contact with the bearing and the yoke. The grounding member is fixed to a ground terminal (32) held by the brush holder.

According to the configuration, the grounding member that comes into contact with the bearing and the yoke is fixed to the ground terminal held by the brush holder. Therefore, a normal contact state of the grounding member can be confirmed at the stage where the brush holder is assembled to the yoke, for example, before the gear housing and the like are assembled to the yoke. Therefore, the grounding member that comes into contact with the bearing and the yoke can be favorably provided.

The above object and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a plan view of a motor according to one embodiment. FIG. 2 is a perspective view of a brush holder according to one embodiment. FIG. 3 is a partial cross-sectional view of the brush holder according to the embodiment. FIG. 4 is a perspective view of a brush holder according to the embodiment. FIG. 5 is a bottom view of the brush holder according to the embodiment. FIG. 6 is a perspective view of a grounding member according to one embodiment. FIG. 7 is a cross-sectional view illustrating a positioning protrusion according to one embodiment. FIG. 8 is an exploded perspective view of a yoke and a brush holder according to one embodiment. FIG. 9 is a sectional view for explaining a yoke contact piece according to the embodiment. FIG. 10 is an electric circuit diagram of a motor according to one embodiment.

Hereinafter, an embodiment of the motor will be described.
As shown in FIG. 1, the motor 10 includes a motor main body 11 and a speed reduction unit 12. The motor body 11 includes a bottomed cylindrical yoke 14 having a magnet 13 fixed to an inner surface thereof, an armature 15 housed in the yoke 14, and a resin brush holder 16 disposed in an opening of the yoke 14. Having. The yoke 14 of the present embodiment is a flat type having a plane portion parallel to the axial direction and an arc portion connecting both ends thereof, and the magnet 13 is fixed to the arc portion.

The reduction portion 12 is accommodated in the gear housing 17 fixed to the opening of the yoke 14, a worm 19 accommodated in the gear housing 17 and integrally rotating with the rotation shaft 18 of the armature 15, and accommodated in the gear housing 17. The worm includes a worm wheel 20 meshed with the worm 19, and an output shaft 20a that rotates integrally with the worm wheel 20.

The armature 15 includes the rotating shaft 18, an armature core 22 that is externally fixed to the rotating shaft 18 and has a winding 21 wound thereon, and a commutator 23 that is externally fixed to the rotating shaft 18. Having.
As shown in FIGS. 1 and 2, the brush holder 16 includes a power supply brush 24 for supplying a current to the armature 15 (specifically, the winding 21 via the commutator 23), and the power supply brush 24 is rectified. It holds a torsion coil spring 25 that urges toward the element 23, a bearing 26 that supports the rotary shaft 18, a capacitor 27 for removing electric noise, a choke coil 28, and the like.

More specifically, the brush holder 16 includes a plate-like base 16a for closing the opening of the yoke 14, a fitting wall 16b extending in the axial direction from the base 16a and fitted into the yoke 14. And an outer extension 16c projecting radially outward from the base 16a and contacting the opening of the yoke 14 in the axial direction. The base 16a of this embodiment corresponds to the shape of the yoke 14 as viewed from the axial direction, has a substantially rectangular shape as viewed from the axial direction, and has an arcuate end at the longitudinal direction. . A pair of power supply brushes 24, a torsion coil spring 25, a capacitor 27, and a choke coil 28 are held inside the fitting wall 16b on the base 16a. At the center of the base 16a, a bearing holding portion 16d that holds the bearing 26 while penetrating is formed. The bearing 26 is provided coaxially with a bearing 29 held at the bottom (upper end in FIG. 1) of the yoke 14 and forms a pair. The bearing 26 supports the rotating shaft 18 together with the bearing 29.

Further, as shown in FIG. 3, a plurality of terminals 30 to 32 are provided on the brush holder 16 by insert molding.
Further, as shown in FIGS. 2 to 5, the brush holder 16 is provided with a substantially plate-shaped metal grounding member 33 that is in contact with the bearing 26 and the yoke 14. The grounding member 33 is fixed to the ground terminal 32 held by the brush holder 16.

Specifically, first, the ground terminal 32 has a caulked portion 32a that protrudes in the axial direction from the bottom surface of the base 16a of the brush holder 16 that is the outer surface of the yoke 14.

As shown in FIG. 5, in the present embodiment, two caulking portions 32 a are provided, and they are located at positions sandwiching the axis center (the center of the rotating shaft 18) L, and at 180 ° intervals with respect to the axis center L. Is provided. Further, the swaging portion 32a of the present embodiment has a bifurcated shape, and is crimped to the grounding member 33 by being plastically deformed in a direction in which the tip sides of the bifurcated shape penetrate the hole and move away from each other (so-called crimping). )

On the other hand, the grounding member 33 has a plate-shaped axial shield portion 33a that covers the bottom surface that is the axial end surface of the brush holder 16, and a plate-shaped radial shield portion 33b that covers the radial outer surface of the brush holder 16. . The axial shield part 33 a of the present embodiment is formed corresponding to the bottom surface of the brush holder 16. The axial shield portion 33a includes a central axial shield portion 33c corresponding to the central portion of the brush holder 16 in the short direction, and a pair of both-end axial shield portions 33d corresponding to both short-side ends of the brush holder 16. And a step portion 33e extending in the axial direction. The step portion 33e connects the central axial shield portion 33c and the pair of both-end axial shield portions 33d. Further, the radial shield portion 33b of the present embodiment is formed to extend in the axial direction from the short-side end of the axial shield portion 33a (that is, the both-end axial shield portion 33d). The portion 16b is formed so as to cover an outer surface in the short direction side which is a substantially flat surface. A through hole 16e is formed in the outer extension 16c of the brush holder 16 so as to penetrate in the axial direction at a position corresponding to the radial shield 33b. The radial shield part 33b is arranged so as to penetrate through the through hole 16e and along the fitting wall part 16b while having a shape simply bent at a right angle from the axial shield part 33a.

The axial shield portion 33a of the grounding member 33, more specifically, the axial shield portion 33d at both ends, has a shape in which a parallel portion and both ends of the parallel portion are connected by an arc at a position corresponding to the caulking portion 32a. Fixing hole 33f is formed. The grounding member 33 is fixed to the ground terminal 32 by a caulking portion 32a that is caulked through the connection fixing hole 33f.

As shown in FIGS. 5 and 7, the brush holder 16 has a positioning protrusion 16f on a surface facing the axial shield portion 33a.
Further, as shown in FIGS. 5 to 7, the axial shield portion 33a has a positioning hole 33g. The axial shield portion 33a is fixed to the brush holder 16 while being positioned in a direction orthogonal to the direction in which the positioning protrusion 16f protrudes by the positioning protrusion 16f crimped through the positioning hole 33g. The caulking of the positioning protrusion 16f is heat caulking. In FIG. 7, the positioning protrusion 16f in a state before heat caulking is shown by a solid line, and the positioning protrusion 16f in a state after caulking is two points. This is illustrated by a chain line.

As shown in FIGS. 4 to 6, the axial shield portion 33a is provided with a pair of bearing contact pieces 33h that are pressed against the bearing 26. The bearing contact piece 33h of the present embodiment is provided such that slits 33j are formed on both sides thereof. Specifically, a circular central hole 33k is formed at the center of the central axial shield part 33c of the axial shield part 33a. The bearing contact piece 33h has a base end provided near the longitudinal end of the central axial shield portion 33c, and a distal end formed to extend closer to the axial center than the central hole 33k. A slit 33j is formed on both sides of the bearing contact piece 33h from the central hole 33k to the base end of the bearing contact piece 33h. The tip end of the bearing contact piece 33h is pressed against the axial end face of the bearing 26 by the spring property of the bearing contact piece 33h. The bearing holding portion 16d has a plurality of holding pieces protruding from the bottom surface of the base 16a of the brush holder 16 and arranged along the circumferential direction. The bearing contact piece 33h is disposed so as to pass through a groove between the holding pieces as viewed from the axial direction, and is provided on the axial end face of the bearing 26 while avoiding contact with the bearing holding portion 16d (that is, the holding piece). Pressing contact.

As shown in FIGS. 8 and 9, the radial shield portion 33b is provided with a yoke contact piece 33m that is pressed into contact with the inner surface of the yoke 14 when the brush holder 16 is inserted into the yoke 14 and assembled. ing. A pair of the yoke contact pieces 33m of the present embodiment is provided in one radial shield part 33b. The yoke contact piece 33m is inclined (axially) so as to extend radially outward toward the opposite side (the lower side in FIG. 9) of the direction in which it is inserted into the yoke 14. In FIG. 9, the yoke 14 and the radial shield portion 33 b including the yoke contact piece 33 m are shown by solid lines before the brush holder 16 is assembled to the yoke 14, and the brush holder 16 is assembled to the yoke 14. The position of the yoke 14 is indicated by a two-dot chain line. When the brush holder 16 is assembled to the yoke 14, the yoke contact piece 33m is pressed in contact with the inner surface of the yoke 14 by its own resiliency while being bent inward on the inner surface. As a result, the grounding member 33 is in contact with the bearing 26 and the yoke 14, that is, is electrically connected to the bearing 26 while being fixed to the ground terminal 32.

As shown in FIG. 10, the motor 10 of the present embodiment has

terminals

30 and 31 that are to be connected to an external power supply, respectively, connected to the first terminal of a capacitor 27, and a power supply brush via a choke coil 28. 24. A second terminal, which is a ground-side terminal of the capacitor 27, is connected to a ground terminal 32, and the ground terminal 32 is connected to the bearing 26 and the yoke 14 as ground by a ground member 33.

Next, the operation of the motor 10 configured as described above will be described.
When a drive current is supplied from an external power supply to the motor 10, a current is supplied to the winding 21 via the

terminals

30 and 31, the choke coil 28, the power supply brush 24, and the commutator 23, and the magnet 13 is attracted and repelled. The armature 15 is rotationally driven by the force. Then, the worm 19 rotates together with the rotating shaft 18 of the armature 15, and the worm wheel 20 and the output shaft 20a meshed with the worm 19 rotate.

At this time, electric noise is generated due to the power supply brush 24 slidingly contacting the commutator 23, but propagation of the electric noise to the circuit side is suppressed by the capacitor 27 and the choke coil 28. Although the electric noise also propagates to the rotating shaft 18, the electric noise may be radiated because the bearing 26 that supports the rotating shaft 18 is connected to the yoke 14 as the ground via the grounding member 33. Be suppressed.

Next, effects of the above embodiment will be described below.
(1) The grounding member 33 contacting the bearing 26 and the yoke 14 is fixed to the ground terminal 32 held by the brush holder 16. Therefore, a normal contact state of the grounding member 33 can be confirmed at a stage where the brush holder 16 is assembled to the yoke 14, for example, before the gear housing 17 and the like are assembled to the yoke 14. Therefore, the grounding member 33 that comes into contact with the bearing 26 and the yoke 14 can be favorably provided. As a result, propagation and radiation of electric noise can be suppressed well.

(2) The ground terminal 32 is connected to the ground terminal of the capacitor 27 for removing electric noise. Therefore, electric noise in the hundreds of MHz band can be effectively suppressed as a Y capacitor.

(3) The ground terminal 32 has a caulked portion 32a, and the ground member 33 has a connection fixing hole 33f. The ground terminal 32 is fixed to the ground terminal 32 by a caulking portion 32a which is swaged through the connection fixing hole 33f. Therefore, for example, the grounding member 33 can be fixed to the grounding terminal 32 while electrically connecting the grounding member 33 and the grounding terminal 32 without using a separate member.

(4) The grounding member 33 has a plate-shaped axial shield portion 33a that covers the axial end surface of the brush holder 16 and a plate-shaped radial shield portion 33b that covers the radial outer surface of the brush holder 16. Therefore, electric noise leaking in the axial direction and the radial direction of the brush holder 16 can be suppressed.

(5) The radial shield portion 33b is provided with a yoke contact piece 33m that is pressed into contact with the inner surface of the yoke 14 when the brush holder 16 is assembled to the yoke 14. Therefore, the ground member 33 can be easily brought into contact with (ie, electrically connected to) the yoke 14.

(6) The yoke contact piece 33m is inclined so as to extend radially outward toward the side opposite to the direction in which the yoke is inserted into the yoke. Therefore, when assembling the brush holder 16 to the yoke 14, the yoke contact piece 33m is not caught and the assembling property is improved.

(7) The axial shield portion 33a is provided with a bearing contact piece 33h pressed against the bearing 26. Slits 33j are formed on both sides of the bearing contact piece 33h. Therefore, the length of the bearing contact piece 33h and the amount of deflection thereof can be ensured to allow the ground member 33 to easily and satisfactorily come into contact with the bearing 26, and a large area of the axial shield portion 33a can be ensured. . That is, for example, in a case where the bearing contact piece is provided without forming a slit on both sides thereof, if an attempt is made to secure the length of the bearing contact piece and, consequently, the amount of bending thereof, the area of the axial shield portion, and hence the brush holder The area that covers the axial end face of the shaft 16 becomes smaller, and the effect of suppressing electric noise leaking in the axial direction becomes smaller. However, this can be avoided. Conversely, when the bearing contact piece is provided without forming a slit on both sides thereof, it is assumed that the area of the axial shield portion, and thus the area covering the axial end face of the brush holder 16, is to be secured. In this case, the length of the bearing contact piece and, consequently, the amount of flexure thereof become small, and it is difficult to make the bearing contact piece come into good contact with the bearing 26, but this can be avoided.

(8) The brush holder 16 has a positioning projection 16f on a surface facing the axial shield 33a, and the axial shield 33a has a positioning hole 33g. The axial shield portion 33a is fixed to the brush holder 16 while being positioned by the positioning protrusion 16f which is crimped through the positioning hole 33g. Therefore, the ground member 33 can be stably fixed with high accuracy by the brush holder 16. That is, in a configuration in which the ground member 33 is simply fixed to the ground terminal 32 held by the brush holder 16, the positioning of the ground member 33 with respect to the brush holder 16 may be insufficient. According to the above configuration, such a fear can be avoided, the fixing force of the grounding member 33 can be further improved, and the falling off of the grounding member 33 can be suppressed.

(9) The brush holder 16 has an outer extension 16c that projects radially outward to abut the opening of the yoke 14 in the axial direction, and the outer shield 16b penetrates the outer extension 16c. Through holes 16e are formed. Therefore, it is not necessary to provide the grounding member 33 with a shape that bypasses the extension 16c, and the grounding member 33 can be formed in a simple shape.

This embodiment can be implemented with the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.
In the above embodiment, the ground terminal 32 to which the ground member 33 is fixed is the one to which the ground terminal of the capacitor 27 is connected. However, the present invention is not limited to this, and the capacitor 27 is not connected. It may be a ground terminal.

In the above-described embodiment, the ground terminal 32 has the caulked portion 32a, and the grounding member 33 is fixed to the ground terminal 32 by the caulked portion 32a which is swaged through the connection fixing hole 33f. However, the present invention is not limited to this. For example, the grounding member 33 may be fixed using another member, such as fixing by soldering. In the above-described embodiment, the swaging portion 32a is so-called crimped in a forked shape, but is not limited thereto, and may be a swaging portion having another shape. Further, it is described that two caulking portions 32a and two connection fixing holes 33f are provided, but one or three or more may be provided.

In the above embodiment, the grounding member 33 includes the plate-shaped axial shield portion 33a that covers the axial end surface of the brush holder 16 and the plate-shaped radial shield portion 33b that covers the radial outer surface of the brush holder 16. But it is not limited to this. The grounding member 33 may not have the axial shield part 33a and the radial shield part 33b, or may have only one of them. Further, the axial shield portion 33a may have a shape without the step portion 33e.

In the above embodiment, the radial shield portion 33b is provided with the yoke contact piece 33m that is pressed into contact with the inner surface of the yoke 14 by attaching the brush holder 16 to the yoke 14, but the present invention is not limited to this. The radial shield part 33b may have a configuration in which the yoke contact piece 33m is not provided. Further, the number and shape of the yoke contact pieces 33m may be changed.

In the above embodiment, the axial shield portion 33a is provided with the bearing contact piece 33h pressed against the bearing 26, and the bearing contact piece 33h is provided such that the slits 33j are formed on both sides thereof. , But is not limited to this. For example, a bearing contact piece provided so as not to form the slit 33j may be used.

In the above embodiment, the brush holder 16 has the positioning protrusion 16f, and the axial shield portion 33a has the positioning hole 33g. The axial shield portion 33a is fixed to the brush holder 16 while being positioned by the positioning protrusion 16f which is crimped through the positioning hole 33g, but is not limited thereto. For example, a configuration without the positioning protrusion 16f and the positioning hole 33g may be adopted. Further, a configuration in which the positioning projections 16f are not crimped, that is, a configuration in which the positioning projections 16f are simply fitted into the positioning holes 33g and used only for positioning may be employed.

In the above embodiment, the brush holder 16 has the through hole 16e formed in the outer extension 16c. However, the present invention is not limited to this, and the brush holder 16 may have a structure in which the through hole 16e is not formed. In this case, for example, it is necessary to provide the ground member 33 with a shape that bypasses the extension 16c.

In the above embodiment, the ground terminal 32 is provided in the brush holder 16 by insert molding. However, the present invention is not limited to this. The terminal 32 may be assembled and fixed to the brush holder 16.

In the above-described embodiment, the present disclosure is embodied in the motor 10 including the motor body 11 and the speed reduction unit 12. However, the present disclosure is not limited thereto, and the present disclosure may be embodied in a motor not including the speed reduction unit 12. . For example, the present disclosure may be embodied in a motor in which an end frame is fixed to the opening of the yoke 14 instead of the gear housing 17.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and the structure. The present disclosure also encompasses various modifications and variations within an equivalent range. In addition, various combinations and forms, and other combinations and forms including only one element, more or less, are also included in the scope and spirit of the present disclosure.

Claims

A bottomed cylindrical yoke (14) having a magnet (13) fixed to the inner surface;
An armature (15) housed in the yoke;
A brush holder (24) disposed at an opening of the yoke and holding a power supply brush (24) for supplying a current to the armature and a bearing (26) for supporting a rotating shaft (18) of the armature; 16)
A grounding member (33) contacting the bearing and the yoke;
The motor wherein the grounding member is fixed to a ground terminal (32) held by the brush holder.
The motor according to claim 1, wherein a ground-side terminal of a capacitor (27) for removing electric noise is connected to the ground terminal.
The ground terminal has a caulking portion (32a),
The grounding member has a connection fixing hole (33f),
3. The motor according to claim 1, wherein the grounding member is fixed to the ground terminal by the caulking portion that is caulked through the connection fixing hole. 4.
The grounding member includes a plate-shaped axial shield portion (33a) that covers an axial end surface of the brush holder, and a plate-shaped radial shield portion (33b) that covers a radially outer surface of the brush holder. Item 4. The motor according to any one of items 1 to 3.
The motor according to claim 4, wherein the radial shield portion is provided with a yoke contact piece (33m) that is pressed into contact with an inner surface of the yoke by attaching the brush holder to the yoke.
The motor according to claim 5, wherein the yoke contact piece is inclined so as to extend radially outward toward a side opposite to a direction in which the yoke is inserted into the yoke.
The axial shield portion is provided with a bearing contact piece (33h) that is pressed against the bearing.
The motor according to any one of claims 4 to 6, wherein the bearing contact piece is provided such that slits (33j) are formed on both sides thereof.
The brush holder has a positioning protrusion (16f) on a surface facing the axial shield portion,
The axial shield portion has a positioning hole (33g),
The motor according to any one of claims 4 to 7, wherein the axial shield portion is fixed to the brush holder while being positioned by the positioning protrusion that is swaged through the positioning hole.
The brush holder has an extended portion (16c) projecting radially outward to abut the opening of the yoke in the axial direction,
The motor according to any one of claims 4 to 8, wherein a through hole (16e) through which the radial shield portion passes is formed in the outer extension portion.